A variety of different reel lowering devices for transferring a reel from a supporting rack for storing empty reel bars into a transfer means to move the reel bars into a winding position have been proposed and many such devices are currently in use. For example U.S. Pat. No. 1,949,997 issued Mar. 6, 1934 to Fourness describes a paper winder wherein empty cores are carried from a lower rack via a pair of arms and moved into winding position against a winding drum to form a roll of paper. The shaft of the paper core is transferred from grooves or slots in the arms transferring the core to the winding position into co-operating slots formed in a second pair of transfer arms that carry a finished or wound roll of paper into a second storage rack located above the storage rack for empty reels. This device provides for the loading and unloading of reels and wound paper rolls respectively from a winding position but is a relatively expensive and cumbersome piece of equipment.
U.S. Pat. No. 2,508,566 issued May 23, 1950 to Dunton describes a web roll backstand and provides for a transfer of a wound roll to an unwind station and removal of the cores. A pair of arms are used to make the transfer into the unreeling position and a second pair of arms are used to transfer the empty reel or core to a second storage position. Although this device is not a device for transferring empty reels into a transfer arm it does show the use of spaced arms to make the transfer of the roll into an operating position.
U.S. Pat. No. 2,989,262 issued June 20, 1961 to Hornbostel teaches the use of gravity to roll a plurality of empty cores and apply the cores one at a time from an inclined storage device into a loading position where they are picked up by a transfer arm and moved into winding position between a pair of winding drums. The mechanism for controlling the flow of empty cores down the relatively steep incline of the storage device leads to significant complications in this structure of the winder.
Yet another example of a reel loader is shown in U.S. Pat. No. 3,586,253 issued June 22, 1971 to Gilbank et al. In this device empty reels are loaded onto an upper rack formed by a pair of rails having an abutment stop at their lower ends so the empty reels move down the rails to the abutment stop. A pair of lifting and lowering arms are provided which lifts each empty reel over the abutment and permits it to roll to the opposite side thereof and then lowers the reel into the reel transfer device. The operation of the reel lowering arms in the arrangement requires lifting the reel over the abutment, transverse movement to direct the reel to the opposite side of the abutment and then lowering of the reel into the transfer device. The opposite side of the abutment in this case operates as a cam to hold the reel in position during the initial phases of lowering of the lowering arms so that there is a controlled movement of the reel along the lowering arms. Obviously the reciprocal motion of the arm during loading complicates the operation of the lowering arms in that they first must move upward to lift the reel bars above the abutment and then downward after the reel bars have moved along the arm to the opposite side of the abutment into a transfer position. U.S. Pat. No. 4,179,329 issued Dec. 18, 1979 to Page discloses an apparatus for handling web material that involves the use of lowering arms similar to that taught by Gilbank et al.
U.S. Pat. No. 3,877,654 issued Apr. 15, 1975 to Randpalu et al utilizes transfer arms as a transfer device in the normal manner to move a reel bar into winding position and also as a lowering mechanism. The transfer arms are extended so that the clamp may move along the arms to an upper position to receive reels located on the storage rack thereabove. Clearly, such extension of the transfer arms requires a controlled movement of the reels along the storage rack to permit the transfer arms to rotate and requires a more elaborate clamping mechanism which is transported along the transfer arms.
In my U.S. Pat. No. 4,744,526 issued May 17, 1988 there is disclosed a reel bar lowering device where the ends of the rails are pivotally connected about a horizontal axis to allow the rail ends to collapse lowering the reel into an initial winding position. In my U.S. Pat. No. 4,744,720 issued May 17, 1988 there is disclosed a reel bar loader device having a pair of lowering arms onto which the reel bars are loaded one at a time. The lowering arms pivot about a horizontal axis from an upper position adapted to receive a reel bar on a supporting surface thereof to a lower transfer position while the reel bar rolls along the length of the surface into contact with an abutment on the arms. The reel lowering arms provide a cam stop that moves into stopping position to stop movement of reel bars into a loading position when the lowering arms are not in their upper position.
Another example of a lowering device including arms that pivot about a horizontal axis is disclosed in Russian Pat. No. 132,933 dated 1959. In this document there is shown a lowering arm over which an elongated bar rolls into a working position where the arms are adapted to load the next bar when the arms rise from a lower position into an upper position.
Still yet another example of a lowering device where a flask is lowered into a transfer device is disclosed in U.S. Pat. No. 3,062,389 issued Nov. 6, 1987 to Hunter. In this device the flask is lowered into the jaws of a transfer station prior to the flask being moved into a lower rack. The lowering arms pivot about a horizontal axis from an upper position prohibiting the flask from moving off the ends of the support rails to a lower position where the flask roll down the lowering arm into the awaiting transfer station. The rate of decent of the flask is a function of the curvature of the lowering arm and is not controlled by any positive means. As a result, the movement of the flask is arrested by the transfer jaws. The momentum associated with this movement increases as the weight of the flask increases thereby placing more of a jarring load on the jaws.
It is also known in a reel lifting device that lifts empty reels onto overhead rails to pivotally connect ends of the rails to the rails themselves where by the ends of the rails pivot outwardly about respective vertical axes. In this arrangement, the rails slope downwardly away from the lifting arm. The lifting arm raises the reel above the rails, the ends of the rails then pivot inwardly to be located below the reels. The lifting arm then lowers the reel onto the ends of the rail whereby the reel is free to roll down the rails away from the lifting arm. While the above device provides for outwardly pivoting rail ends, the device still requires the use of a lifting arm that pivots about a horizontal axis and is designed to carry the entire weight of the empty reel. Further, while I have modified the reel bar lifter design for use in a lowering device, such a device still requires the use of a lifting and lowering arm that first lifts the reel off the ends of the rails, and then lowers the reel into winding position. Such lifting and lowering devices must carry the entire weight of the reel during the lifting or lowering which becomes more critical for larger and heavier reels.
The above reel lowering device mechanisms either require lifting and lowering of the reel in a lowering arm mechanism or they require that the reel be lowered by pivoting arms that pivot about a horizontal axis. However when heavy reels in the order of 12,000 kg are used with these reel lowering arms to control lowering of the reel from the support rails down into the transfer arms the safety factor in using these arms becomes more critical since failure of the lowering arm may result in collapse of the lowering device and free fall of the reel. Should the reel bar lowering arms not be able to cope with the weight of the reel and fail, the lowering arm may collapse downwardly dropping the reel. Thus the use of heavier reels may adversely effect the safety factor.